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media: videobuf2-v4l2: Expose vb2_queue_is_busy() to drivers

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vb2 queue ownership is managed by the ioctl handler helpers
(vb2_ioctl_*). There are however use cases where drivers can benefit
from checking queue ownership, for instance when open-coding an ioctl
handler that needs to perform additional checks before calling the
corresponding vb2 operation.

Expose the vb2_queue_is_busy() function in the videobuf2-v4l2.h header,
and change its first argument to a struct vb2_queue pointer as the
function name implies it operates on a queue, not a video_device.

Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
This commit is contained in:
Laurent Pinchart 2022-03-18 18:44:35 +01:00 committed by Mauro Carvalho Chehab
parent 117368f0c4
commit 7101d12799
2 changed files with 31 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
drivers/media/common/videobuf2/videobuf2-v4l2.c
View File

@ -977,12 +977,6 @@ EXPORT_SYMBOL_GPL(vb2_poll);
* and so they simplify the driver code.
*/
/* The queue is busy if there is a owner and you are not that owner. */
static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file)
{
return vdev->queue->owner && vdev->queue->owner != file->private_data;
}
/* vb2 ioctl helpers */
int vb2_ioctl_reqbufs(struct file *file, void *priv,
@ -997,7 +991,7 @@ int vb2_ioctl_reqbufs(struct file *file, void *priv,
p->flags = flags;
if (res)
return res;
if (vb2_queue_is_busy(vdev, file))
if (vb2_queue_is_busy(vdev->queue, file))
return -EBUSY;
res = vb2_core_reqbufs(vdev->queue, p->memory, p->flags, &p->count);
/* If count == 0, then the owner has released all buffers and he
@ -1026,7 +1020,7 @@ int vb2_ioctl_create_bufs(struct file *file, void *priv,
return res != -EBUSY ? res : 0;
if (res)
return res;
if (vb2_queue_is_busy(vdev, file))
if (vb2_queue_is_busy(vdev->queue, file))
return -EBUSY;
res = vb2_create_bufs(vdev->queue, p);
@ -1041,7 +1035,7 @@ int vb2_ioctl_prepare_buf(struct file *file, void *priv,
{
struct video_device *vdev = video_devdata(file);
if (vb2_queue_is_busy(vdev, file))
if (vb2_queue_is_busy(vdev->queue, file))
return -EBUSY;
return vb2_prepare_buf(vdev->queue, vdev->v4l2_dev->mdev, p);
}
@ -1060,7 +1054,7 @@ int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p)
{
struct video_device *vdev = video_devdata(file);
if (vb2_queue_is_busy(vdev, file))
if (vb2_queue_is_busy(vdev->queue, file))
return -EBUSY;
return vb2_qbuf(vdev->queue, vdev->v4l2_dev->mdev, p);
}
@ -1070,7 +1064,7 @@ int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p)
{
struct video_device *vdev = video_devdata(file);
if (vb2_queue_is_busy(vdev, file))
if (vb2_queue_is_busy(vdev->queue, file))
return -EBUSY;
return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK);
}
@ -1080,7 +1074,7 @@ int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i)
{
struct video_device *vdev = video_devdata(file);
if (vb2_queue_is_busy(vdev, file))
if (vb2_queue_is_busy(vdev->queue, file))
return -EBUSY;
return vb2_streamon(vdev->queue, i);
}
@ -1090,7 +1084,7 @@ int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i)
{
struct video_device *vdev = video_devdata(file);
if (vb2_queue_is_busy(vdev, file))
if (vb2_queue_is_busy(vdev->queue, file))
return -EBUSY;
return vb2_streamoff(vdev->queue, i);
}
@ -1100,7 +1094,7 @@ int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p)
{
struct video_device *vdev = video_devdata(file);
if (vb2_queue_is_busy(vdev, file))
if (vb2_queue_is_busy(vdev->queue, file))
return -EBUSY;
return vb2_expbuf(vdev->queue, p);
}
@ -1152,7 +1146,7 @@ ssize_t vb2_fop_write(struct file *file, const char __user *buf,
return -EINVAL;
if (lock && mutex_lock_interruptible(lock))
return -ERESTARTSYS;
if (vb2_queue_is_busy(vdev, file))
if (vb2_queue_is_busy(vdev->queue, file))
goto exit;
err = vb2_write(vdev->queue, buf, count, ppos,
file->f_flags & O_NONBLOCK);
@ -1176,7 +1170,7 @@ ssize_t vb2_fop_read(struct file *file, char __user *buf,
return -EINVAL;
if (lock && mutex_lock_interruptible(lock))
return -ERESTARTSYS;
if (vb2_queue_is_busy(vdev, file))
if (vb2_queue_is_busy(vdev->queue, file))
goto exit;
err = vb2_read(vdev->queue, buf, count, ppos,
file->f_flags & O_NONBLOCK);

23
include/media/videobuf2-v4l2.h
View File

@ -302,10 +302,29 @@ __poll_t vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait);
* The following functions are not part of the vb2 core API, but are simple
* helper functions that you can use in your struct v4l2_file_operations,
* struct v4l2_ioctl_ops and struct vb2_ops. They will serialize if vb2_queue->lock
* or video_device->lock is set, and they will set and test vb2_queue->owner
* to check if the calling filehandle is permitted to do the queuing operation.
* or video_device->lock is set, and they will set and test the queue owner
* (vb2_queue->owner) to check if the calling filehandle is permitted to do the
* queuing operation.
*/
/**
* vb2_queue_is_busy() - check if the queue is busy
* @q: pointer to &struct vb2_queue with videobuf2 queue.
* @file: file through which the vb2 queue access is performed
*
* The queue is considered busy if it has an owner and the owner is not the
* @file.
*
* Queue ownership is acquired and checked by some of the v4l2_ioctl_ops helpers
* below. Drivers can also use this function directly when they need to
* open-code ioctl handlers, for instance to add additional checks between the
* queue ownership test and the call to the corresponding vb2 operation.
*/
static inline bool vb2_queue_is_busy(struct vb2_queue *q, struct file *file)
{
return q->owner && q->owner != file->private_data;
}
/* struct v4l2_ioctl_ops helpers */
int vb2_ioctl_reqbufs(struct file *file, void *priv,